Material requirements planning (MRP) is an inventory management system which is planned to help companies in scheduling and placing orders for items of dependent demand. Dependent demand items represent components of finished goods, such as raw materials, component parts, and subassemblies for which level of production of the final product is main source to adjust the amount of inventory needed. There are three main questions to be answered by MRP: what is needed? how much is needed? and when is it needed?